move range and delay over to util module

src/session.js

@@ -17,6 +17,7 @@ limitations under the License.
 const puppeteer = require('puppeteer');
 const Logger = require('./logger');
 const LogBuffer = require('./logbuffer');
+const {delay} = require('./util');
 
 module.exports = class RiotSession {
     constructor(browser, page, username, riotserver, hsUrl) {
@@ -169,7 +170,7 @@ module.exports = class RiotSession {
     }
 
     delay(ms) {
-        return new Promise(resolve => setTimeout(resolve, ms));
+        return delay(ms);
     }
 
     close() {